Alfalfa is grown for hay, pasture and silage, and is valued highly as a livestock feed. Alfalfa is highly effective in nitrogen fixation, and is frequently planted in crop rotation to replenish nutrients depleted from the soil by other crops such as corn. Alfalfa is an herbaceous perennial legume characterized by a deep tap root showing varying degrees of branching. The plants have erect or semi-erect stems, bearing an abundance of leaves, and grow to a height of 2-4 feet. The number of stems arising from a single woody crown may vary from just a few to 50 or more. New stems develop when older ones mature or have been cut or grazed. Flowers are borne on axillary racemes which vary greatly in size and number of flowers. Flower color is predominantly purple, or bluish-purple, but other colors occur. The fruit is a legume, or pod, usually spirally coiled in M. sativa. Seeds are small, with about 220,000/lb., and the color varies from yellow to brown.
Alfalfa is widely adapted to temperature and soil conditions, except for humid tropical conditions. Reproduction in alfalfa is mainly by cross-fertilization, but substantial self-pollination may also occur. Cross-pollination is effected largely by bees. Two species of alfalfa, M. sativa and M. falcata, have become important forage plants with Medicago sativa L. (also known as lucerne) being one of the world's most valuable forage legumes.
Increasing alfalfa fiber digestibility by decreasing lignin content is known to improve forage quality, ration formulation flexibility, and enhance feed value. Doing so while not adversely affecting yield and without having to introduce transgenes to develop stable, high yielding varieties with low or reduced lignin content has long been a goal of alfalfa breeders. U.S. Pat. No. 9,648,826 discloses one variety having reduced lignin content. However, additional alfalfa varieties are desired that have reduced Acid Detergent Lignin (ADL) content compared to known alfalfa varieties.
The commercial production of seeds for growing alfalfa plants normally involves four stages, the production of breeder, foundation, certified and registered seeds. Breeder seed is the initial increase of seed of the strain which is developed by the breeder and from which foundation seed is derived. Foundation seed is the second generation of seed increase and from which certified seed is derived. Certified seeds are used in commercial crop production and are produced from foundation or certified seed.